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Monday, September 14, 2015

Partial Solar Eclipse Darkened the Sky on Sunday

A partial solar eclipse has blocked out the sun on Sunday, the first part of a month of stunning astronomical events. The solar eclipse was only visible in the sky to those in the southern part of Africa – including people in South Africa, Mozambique, Zambia, Zimbabwe and Madagascar – and in Antarctica. But livestreams and photos allowed anyone to tune into the eclipse as it happened, and stunning pictures have been shared after the event.

NASA’s Solar Dynamics Observatory, or SDO, kept up its constant watch on the sun, its view was photobombed not once, but twice. Just as the moon came into SDO’s field of view on a path to cross the sun, Earth entered the picture, blocking SDO’s view completely. When SDO's view of the sun emerged from Earth’s shadow, the moon was just completing its journey across the sun’s face.

Though SDO sees dozens of Earth eclipses and several lunar transits each year, this is the first time ever that the two have coincided.

SDO’s orbit usually gives us unobstructed views of the sun, but Earth’s revolution around the sun means that SDO’s orbit passes behind Earth twice each year, for two to three weeks at a time. During these phases, Earth blocks SDO’s view of the sun for anywhere from a few minutes to over an hour once each day.

ESA’s sun-watching Proba-2 satellite experienced three partial solar eclipses. The spacecraft orbits Earth about 14.5 times per day, dipping in and out of the Moon’s shadow around the time of a solar eclipse. The constant change in viewing angle of Proba-2 meant that the satellite passed through the shadow three times during the eclipse yesterday.

Proba-2 solar eclipse. Credit: ESA/Royal Observatory of Belgium

The next solar eclipse will happen on March 9, 2016, and will be visible in Asia, Australia and the Pacific and total in Sumatra, Borneo, Sulawesi, Pacific. That eclipse will be almost exactly a year after the last one – a total eclipse that was visible across Europe.

But that’s far from the next exciting astronomical event in the calendar. On the night of September 27-28, there will be a number of strange goings in the sky – both a lunar eclipse and a super moon, which will mean that the moon is at the darkest and lightest it has been all year, in the same night.

And in 2017, there will be a solar eclipse over America that will bring the biggest single movement of people for tourism in human history.